Dark City asks: Who are you, if you can't remember who you are?

The science-fiction works of the late, great Philip K. Dick haven't been served particularly well on screen. The most recent adaptation, Screamers, was junk; Total Recall had its moments but was less ingenious by half than the short story it was based on. Blade Runner, of course, was brilliant, but in ways that only tangentially reflect Dick's thematic concerns.

Dark City, the new film from Alex Proyas, director of The Crow, isn't technically based on Dick, but in most regards it's closer in spirit to his works than any of the official adaptations. It opens with a setup that is both classic film noir and perfectly Dickian: John Murdoch (Rufus Sewell, the hunk from Cold Comfort Farm) awakens in a strange hotel room with no idea how he got there or, for that matter, who he is. A phone call warns him to leave at once; he escapes just before the arrival of a bunch of sinister, deathly pale men, who look precisely like Christopher Lloyd's Judge Doom in Who Framed Roger Rabbit. (In other scenes, they're indistinguishable from the Borg in Star Trek: The Next Generation.)

In fairly short order, Murdoch is being chased both by the Strangers (as the film comes to refer to these weird ghouls) and by the police, led by the accordion-playing detective Frank Bumstead (William Hurt), who suspects him of a series of murders. Murdoch can't be sure he's not guilty, even as he begins to recover brief flashes of his memories, helped along by his torch-singer wife, Emma (Jennifer Connelly), and by his "therapist" -- the bizarre Dr. Schreber (Kiefer Sutherland).

The question the film gradually poses, however, is not, "What will Murdoch's memories be?" but, "Are these his memories? Or someone else's? And would it make any difference?"

Little by little, both Murdoch and the viewer begin to notice that there's something, well, a little off about the milieu where all this is taking place. Everybody seems to remember a place called Shell Beach, but no one can quite recall how to get there. And -- in what is a droll comment on noir cinematography -- we realize that it's always night. "When was the last time you remember doing something during the day?" Murdoch asks Bumstead, who doesn't quite want to admit that he can't remember.

Indeed, the more that Murdoch and the audience discover about what's going on, the less clear it becomes that anything in Dark City's world is to be taken at face value. The film passes out of the realm of such amnesiac noir fare as Mirage, Night Without Sleep and Somewhere in the Night, through the quasi-science-fictional Groundstar Conspiracy and all the way into the world of Dick's Time Out of Joint and Flow My Tears, the Policeman Said.

It would be tough to discuss Dark City in much more detail without giving everything away, were it not that the trailers and the ads have already done so. (Still, if you've missed the trailers and the ads, you might want to skip the next two paragraphs.)

We eventually learn that the Strangers are aliens who have kidnapped all the characters from Earth and relocated them on a floating lab in the middle of the cosmos. The Strangers, like aliens since time immemorial, need to take over our bodies and our planet. These noncorporeal creatures are temporarily occupying human corpses -- hence their pasty, emaciated forms -- but they look forward to moving into some real bodies.

First, though, they have to find out what this soul thing is that makes us tick. So they've created an unreal city from an amalgam of their victims' memories. (This pretty much absolves the images of any complaints of being too derivative: The plot requires that they be derivative.) And every night, they put all the humans to sleep and sneak around extracting people's memories from their brains and injecting them into other people. (They also redesign the city to match the new memory configurations -- which provides an excuse for some really great morphing effects.) By comparing how different people behave when equipped with the same identities and memories, they hope to cancel out other factors and zero in on the pure essence of being human.

Dark City is full of provocative concepts, but, like most films that attack such metaphysical concerns head-on, things have become a tad too jumbled by the end to be altogether satisfying. It's a problem built into the subject matter. In truth, even Dick's books often felt like cheats at the end. To build a plot around inherently unsolvable questions is to paint oneself into a corner.

The performances are a mixed bag, although their weak points, like the film's derivative visual elements, are almost mandated by the story itself. That is, we never really get a handle on anybody's personality, since there are, by definition, no real personalities to get a handle on. Murdoch may or may not even be Murdoch.

The one character whose function in the story suggests a true identity is Schreber, who could have provided a surer foothold for audience identification. But either Proyas or Sutherland (or both) made the odd decision to have Schreber be the least real character of all. It's hardly the actor's best work: Schreber limps around with a twisted face, an accent and an unnatural, contraction-free mode of speech, like some kind of over-the-top amalgam of Peter Lorre, Oskar Homolka and Dwight Frye in a grade-Z horror movie. It's not clear whether the portrayal is supposed to be funny, but funny it is.

This all said, Dark City is immensely entertaining, as well as visually dazzling; the film's look is something like The Crow, but even more imaginative. Proyas has obviously looked long and hard at a wide range of foreign films, most obviously City of Lost Children and Zentropa. He's assimilated their influences into his own idiosyncratic version of an American-style noir.